Machine for shaping metal workpieces



June 8, 1954 A. M. REDMAN MACHINE FOR SHAPING METAL WORKPIECES Fried Jan-26, 1951 June 8, 1954 A. M. REDMAN MACHINE FOR SHAPING METAL WORKPgEQESFiled Jan. 26, 1951 Jr Z 29 20 June 8, 1954 M, REDMAN 2;80,467

MACHINE FOR SHAPING METAL WORKPIECES Filed Jan. 26, 1951 3 Sheets-Sheet3 m e-MM? Patented June 8, 1954 UNITED STATESv 2,680,467 7 MACHINE FORSHAPING METAL WORKPIECES n, Croydon, England, asools & Products Limited,British company Albert Maurice Redma signor to 'Redman T Croydon,England, a

Application January 26, 1951,

10 Claims. 1

This invention comprises improvements in or relating to methods ofshaping metal work-pieces and to metal-working machines therefor, andits object is to provide an improved method and construction of machinefor the cold bending and shaping of work-pieces such as metal bars,rods, strips, tubes and the like, which method and machine are moreoverparticularly suitable for bending work-pieces into the form of acomplete ring or closed figure, or for shaping those which are alreadyin this form.

According to the present invention a method of shaping a metalwork-piece consists in placing the work-piece against a former, pressinga shoe on to the Work-piece toward the former, so that the shoe forcesthe work-piece to conform to the former at one part of its length, andthereafter while maintaining pressure on the shoe toward the former,shifting the place of application of such pressure progressively alongthe shoe and e shoe and former one over the other with the work-piecebetween them to cause the metal of the Work-piece to flow intoconformity with the shape of Preferably the further comprises in aSerial No. 207,879

to swing it is obviated and this fact is not only an advantage in itselfbut renders a machine according to the present v as Patent No. 2,636,537enables curved flanged the combination of a former, a press-memberopposed to the former so as to bear on a work-piece placed on theformer, a fluid-.pressure-operated ram behind the pressmember to urge ittoward the former, a carrier on shoe can act progressively along thework-piece without lateral sliding movement thereon.

along the back of the shoe, the movement being somewhat analogous tosliding about its fulcrum and the shoe work-piece. Thus the need forproviding some independent means, such as a Winch or hydraulictraversing cylinder, to haul or push upon the arm rolls upon the work tobe produced without undesirable distortion or crinkles. The shoe pressesthe workpiece against the former over a narrow area "only at any onetime and this narrow area of pressure is caused to travel slowly andprogressively over the Work-piece so that the metal of the workpieceflows and the work-piece is gradually smoothed or ironed to the shape ofthe former;

work-piece show a very slight thickening toward their edges along theinside of the curve.

In the preferred form the movement of the fulcrum of the carrier iseffected by two hydraulic piston and cylinder units acting in directionssubstantially at right-angles to one another. The may swing, in asubstantially complete ring. 7

L One form of machine in accordance with the invention will now bedescribed, byway of example, and with reference to the accompanyingdiagrammatic drawings in which:

Figure 1 is a diagrammatic plan view of the machine, a Figure 2 is adiagrammatic elevation in part section on the line 2-2 of Figure 1,

Figure 3 is a further diagrammatic plan view showing the parts indifferent relative positions to those of Figure 1,

Figure 4 is a diagram to illustrate the movements of the carrier and itsfulcrum during operation of the machine,

Figure 5 shows a former block for the machine in plan view, and

Figure 6 is a diagram to illustrate further the operation of themachine.

The machine has a frame H comprising a base plate 12, side walls 13 anda rear wall M. A bridge member l5 extends across the top of the machinenear the front thereof between the side walls I3, and secured to theunderside of the bridge member midway along its length is a formersupport 40 carrying on its underside a male former having a profile 11which is elliptical in plane and semi-circular in verticalcross-section. The elliptical former is symmetrically mounted withrespect to the bridgemember l5, with its major axis parallel to the sidewalls 13.

At the lower part of the machine two vertically spaced horizontal platesl8, l9 extend across the machine between the side walls and from thefront to the rear, the lower plate 18 being supported at the front ofthe machine by a low vertical wall 20. A fulcrum block 2|, which iscircular in plan, slides horizontally between the two plates i8, i9 andhas journalled in it a vertical pivot pin 22 disposed directly beneaththe former l6, which pin serves as a fulcrum about which swings anelongated horizontal cantilever arm 23, shown extending forwardly of themachine in Figures 1 and 2. The circular fulcrum block has an internalcavity 24 through which the pivot pin 22 passes.

The cylinders 25, 25 of a pair of hydraulic piston and cylinder unitsare arranged horizontally between the plates l3, l3 and are pivotallyconnected to the machine frame, one near each rear corner of the frame.The cylinders have piston rods 21, 28 which extend towards the fulcrumblock 21, the two piston and cylinder units being arranged very nearlyat right-angles to one another as viewed in plan, and the rods pass intothe cavity 24 within the block 2| through apertures in the wallsurrounding the cavity. The piston rod 28 has an eye 29 and the pistonrod 21 a forked eye 30, and the pivot pin 22 journalled in the fulcrumblock 2! passes through the eyes 29, 30 the eye 29 being fitted betweenthe forks of the eye 30. Thus it will be clear that the fulcrum block 21and pivot pin 22 for the arm 23 are movable bodily in any direction in ahorizontal plane under the control of the two cylinders 25, 26,; theupper horizontal plate 19 having an aperture 3| to allow the pivot pinto move laterally. The elongated arm 23 is therefore capable of swingingin a horizontal plane about its fulcrum 22 located within the closedfigure of the profiled face of the former IS in a manner to change thecrossing angle of the longitudinal axis of arm 23 and the former profileand through a complete revolution of the former.

The arm 23 has secured face a horizontal strap 32, and a second parallelstra 33 is spaced vertically above the strap 32 and is also secured toswing with the arm. The cylinder 34 of a horizontal hydraulic piston andcylinder unit is mounted between the outer ends of the straps 32, 33 andhas a piston rod 35 extending parallel with the arm toward a verticalprojection of the pivot pin 22. The axis of the piston rod 35 is on alevel with the horizontal centre-line of the former profile l1, and thestraps 32, 33 are spaced equi-distantly below and above the formerrespectively. Towards its in-- nor end, that is the end nearer the pivotpin, the lower strap 32 is broadened out to form a table 36 which swingswith the arm 23.

A shoe 31, for shaping the work-piece upon along its upper surthe formerI6, is constituted by a heavy cast mild steel block, rectangular in planand in crosssection, and resting horizontally upon the table 36 overwhich it is free to slide beneath the upper strap 33. The block 31 has ahorizontal recess 38 extending along its surface which faces H5, andthree hardened steel inserts or liners 33 are fitted along the side andbottom faces of the recess, to resist wear and are so shaped that whenthey are in position the vertical cross-section of the recess, which isuniform along the whole length of the recess, is semi-circular tocorrespond to the shape of the outer or convex surface of the finishedwork which it is desired'to produce upon the machine. The longitudinalcentre-line of the recess 38 is at the same height as that of the maleformer profile I6, and the shoe 31 with its longitudinal recess 33constitutes a female former movable with respect to the male former 16,with which it cooperates to shape a work-piece held in place between theformer l6 and the shoe The piston rod 35 of the piston and cylinderunit, mounted on the swinging arm 23, has at its inner end a forkedadaptor ii which carries a roller 42 mounted centrally of the arm 23 torotate about a vertical axis, and under the action of the hydrauliccylinder 34 the roller 32 bears upon the back of the shoe 31 to causethe shoe to shape a work-piece against the former If.

The operation of the machine will now be described. The pressure exertedby the hydraulic cylinder 34, clearly, always acts along the centrelineof the swinging arm 23, directly towards a vertical projection of thepivot pin 22; when this line of pressure is normal to the horizontalcentre-line of the work-piece on the former it at that part thereof uponwhich the shoe 31 is hearing, the arm is stable and shows no tendency toswing, but if the line of pressure and the horizontal centre-line ofsaid part of the work-piece on the former are at an angle to one anotherother than then it will be seen that the force due to the pressure ofthe cylinder 34 can be resolved into a component normal to the former l5and work-piece and a component parallel thereto, and the lattercomponent of force tends to cause the arm 23 with the hydraulic pressurecylinder 34 to swing about its pivot 22. By moving the fulcrum block 2!under the control of the hydraulic cylinders 25, 23 it is possible toadjust the line of pressure of the cylinder 33 angularly with respect tothe former l3 and workpiece until a point is reached when the aforesaidparallel component of force becomes sufiicient to overcome thefrictional forces of the parts and the resistance of the work-piece tothe shoe 31 and therefore to swing the arm 23, and it will be realisedthat the arm 23 can be kept swinging, or stopped, or caused to swing inthe reverse di rection merely by effecting suitable movements of thefulcrum block 21, and that the speed of swing is controllable in thesame manner.

Thus, by mounting the swinging arm 23 of the bending machine accordingto the present invention in such manner that the fulcrum block 2| ismovable at will as desired, the need for providing independent means,such as a winch or hydraulic traversing cylinder, for swinging the armby hauling or pushing upon it, as is often found in bending machines, isobviated. In the machine illustrated'and described herein, the arm 23and the pressure cylinder 34 it carries are capable of rotating througha complete revolution about the pivot pin 22 and around the former Hi,the arm 23 passing beneath the bridge-member l5 and swinging in thespace within the side walls 13 and rear wall 14 of the machine frame H,and when the hydraulic cylinder 33 is exerting pressure the arm 23 maybe caused to perform such a revolution, either in stages orcontinuously, as

towards the former the swinging arm 23 and section in one and the sameoperation, but shaping of the cross-section of a work-piece will beonly, for the sake of simplicity). The dimensions of the profileperiphery l1 and the inner dimensions of "the ring to be shaped, asconsidered in plan View, are substantially the same, and the Work-pieceis placed around the elliptical former profile [7, after having first ofthe fulcrum and swinging arm at 51 and it, respectively, and theposition of shoe 3? atthe commencement of the forming operation isrepresen ed at '52. The position of the fulcrum on the major axis of theformer ellipse and intermediate between the central position 5i and theprojection of the former outline as is represented. at 53 and the dottedline '5'i53 indicates the path of the forward movement followed by thefulcrum.

The shoe 3? is positioned so that the right-hand of it, as viewedlooking :along the arm toit with the work-piece thereon, pressure isthen applied by the cylinder 34 so that the shoe is forced toward anddriven tightly on to it around the work-piece, which is represented'inFigures 1, 2'and 3 in phantom lines at H, over a limited area in frontof the roller. This action shapes the work-piece to the former profileand gives it the required semi-circular cross-section over part of thelimited area of the work-piece with which the shoe is now in contact.

quently the arm 23 is translated from the stable condition in which theline of pressure of the hydraulic cylinder is coincident with the majoraxis of the former :l 6 into .an unstable condition in which there is acomponent of force tending .to move the arm .23 bodily .to the left, andas the plan, and follows the fulcrum.

The unstable condition of the .arm is illustrated in plan View in Figure:6, in which the line of pressure P of the hydraulic cylinder lies atanangle other than to a line T tangential to the part of the former I6upon which the shoe 3! is thcshoe :upon the work-piece is transferredgradually and progressively along the work-piece, and

work-piece between the shoe 3-! and male former cross-section of thework-piece as the shoe rolls thereon, the work is formed withoutproducingany undesirable crinkles or distortion; "the metal thickens upslightly on the inside of the curve but is not over-strained in any way.

developed length of ithe' for'mer first stage the fulcrum is moved alongthe path 54 to a position 55, and

stage, and finally forwardly and to the left along position :53 for thefourth stage and to completethe cycle. Ihe arm v23 is in the positionsshown dotted line at 62 and t3 when the fulcrum is at rest ,in positions58 and 60 "respectively, andin each position the pressure of thecylinder 34 is released and the shoe 3'! the swinging arm in the presentmachine has a is slid from right to left across the table, as viewedmoving fulcrum, sim'lar circumstances, dependlooking along the arm 23towards the fulcrum. ent upon the curvature of the part of the formerWhen the shaping of the work-piece has been against which the shoe ispressing the work-piece, completed, the pressure on the back of the shoe5 affect its movement; for example, the arm will 31 is released and theshoe is removed from the tend to speed up when the shoe is shaping thework; the finished work can then be replaced by a first and thirdquarters of the work-piece and will fresh work-piece and the cycle ofoperations rebe slowed down when forming the second and peated. Theformer is collapsible, being made up fourth quarters. The constantdelivery pump and from a number of sections detachable one from theaforementioned relief valve keep the pressure another, in order that itshall be capable of reexerted by the cylinder 34 substantially constantmoval from the finished work-piece which surwhether the movement of theshoe 31 is uphill rounds it, or downhill, but it is also important toensure Thus, Figure 5 shows in plan an elliptical that the movement ofthe arm 23 and shoe 31 former made up of five separable sections 64, 65,should be sufliciently slow to allow the metal of 6B, 61, 68, withdisconnectable brackets 59 for the Work-piece time to flOW as it is pand holding the sections together, and it will be clear this may beeffected either by varying the path that after a double-flangedwork-piece has been of the fulcrum or by slowing up the fulcrum bent toshape around the former, the former may movement over the parts of itspath which it be removed by first knocking out the middle ec-- traverseswhen the shoe is moving downhill so tion 68 and then sliding firstsections 86 and 61', that unduly rapid folding action upon the workandthen sections 64 and 65, inwards. piece is prevented from occurring atany point in It is to be understood that Figure 4 is merely a e cycle.diagram for the purpose of explaining the work- Although a particularmachine and the p oducing of the machine and that the path of th fultionof a specific form of work is described herein crum shown is only anapproximate one; moreby way of example, it will be appreciated that overalthough the arm 23 is represented at 54, 62 considerable modificationand addition is possible and 63 as being in each case in a positionnormal without depart n from the Scope of the vento the horizontalcentre-line of the work-piece tion.

and former at that point, this will not in actual In most cases it isdesired to clamp the Workfact be so, as the arm 23 always tends to lagpiece to the former at some stage in the operabehind the fulcrum in itsswinging owing to the ti n n f n hr h the bending n h pfriction in themachine and the resistance of the ing operation and for this purpose ahydraulic work-piece to the shoe 31. This can be comclamp such as thatupon the machine described pensated for at the end of each cycle bycarrying in the above mentioned Patent No. 2,636,537, or the fulcrumpast the position 53 for a short dis a n mb r f h lamps, c uld bprovided. If tance in order to bring the arm 23 round in front desired,an au y Shoe control y u c ylof the machine far enough to complete theshapi r as described in a -p nd s appli ation ing of the work-piece; thefulcrum can then, if m y be car ied by the swinging arm to assist indesired, be returned to the position 53 for com- Sw t S angu rly and inpulling the mencement of the next working cycle. shoe off the work, towhich it may tend to stick.

Figure 3 shows in plan view the parts of the I claim: machine in therelative positions which they n a m ta -Work ma hine the combinaoccupynear the completion of the shaping of the tion of a machine frame, aformer secured on said first quarter of the work-piece. frame and havinga front face to receive a work- The pressure employed in forming theworkpiece for shaping, an elongated arm mounted on piece is high; it maybe of the order of 2,000 lbs. the frame to be capable of swinging infront of per square inch. The hydraulic pressure is conthe former abouta fulcrum located behind the veyed to the various cylinders of themachine by former in a manner to change the crossing angle reinforcedflexible pipes, not shown in the drawof the longitudinal arm axis andthe former proings. A constant delivery type pump is automafile, saidfulcrum being movable upon the machine tically controlled to maintainthe working presframe in the plane in which the arm swings about sure inthe various hydraulic circuits. An adsaid fulcrum to afiord pivotalmovement of the justable relief valve is provided in the pressure armabout different parallel axes, a press-member line to the swingingpressure cylinder 3 in order u rted in front of the former t be on toprevent excessive fluid pressure in said cylinder work-piece placedagainst the former, fluid-presduring shaping of the work-piece.sure-operated means mounted on the arm to urge It will be understoodthat, in a bending mathe press-member toward the former, and fulchineWith an arm having 2- fixed fulcrum and crum-moving mean mounted uponthe machine provided w th a pr s Cylinder and a S110e frame andoperatively connected to the arm at similar to that of the presentmachine to roll on t fulcrum end theregf behind t former for the Wo -pexample a machine as moving said fulcrum to various positions behindscribed in the above mentioned Patent N the former to cause the arm,under the effect of 537, when the shoe is pressing the work-piece topressure applied to the work-piece by the fluida p Of the former Wherethe distance f 5 pressure-operated means and press-member, to formerprofile from the pivot of the arm 1s mswing and hift the place ofapplication f pres creasing, there will be increased resistance to thesure progressively along t workpiece progress of the swinging arm a ompwith 2. In a metal-working machine the combinawhen the distance o eformer P fi from the tion of a machine frame, a former secured on saidDivot is constant, whereas when said distance is frame and having acurved front face to receive decreasing the resistance to swinging isdecreased. a workpiece for shaping, an arm mounted on the Theseconditions under which the resistance to frame to swing in front of theformer about a swinging is increased or decreased may be repivot pinlocated behind the former, a fulcrum garded as analogous to uphill ordownhill block in which the pivot pin is journalled which movement ofthe shoe respectively. Although block is mounted to slide upon the framein any on a workpiece placed against the pressure-operated workpiece bythe fluid-pressure-operated means and press-member, to swing andshiftthe place of application of pressure progressively along the workpiece.

3. Ina metal-working machine the combination of a machine frame, aformer secured on said frame and having a curved front face to receiveplaced against the former, fiuid-pressure-operated means mounted on thearm to press the shoe 10 to the workpiece by the shoe progressivelyalong the workpiece.

nose to apply the pressure to the shoe which nose moves laterally as t earm swings thereby shifting the place of contact between nose and shoealong the shoe, and fulcrum-movingcause the arm, when pressure theworkpiece the shoe progressively along 6.- In a metal-working machinethe combination of a machine frame, a

of the former about a pivot pin located behind the former, a fulcrumblock in which the pivot pin is journalled, which block is'mounted toslide between guide plates upon the frame in any direction in the planein which the arm swings about such pivot pin to afford pivotal movementof the arm about different parallel axes, a press-member supported infront of the former to bear on a workpiece placed against the former,fluid-pressure-operated means mounted on the arm to urge thepress-member toward the former, and a pair of hydraulic piston andcylinder units mounted upon the machine frame with their axes lyingsubstantially at right angles to one another in the plane of movement ofthe fulcrum block, said piston and cylinder units being operativelyconnected to the fulcrum block for sliding it to various positions tocause the arm, when pressure is applied to the workpiece by thefluid-pressureoperated means and press-member, to swing and shift theplace of application of pressure progressively along the workpiece. 8.In a metal-working machine the combination of a machine frame, a formersecured on said frame and having a curved front face to receive aworkpiece for shaping, an arm mounted on the frame to swing in front ofthe former in a horizontal plane about a pivot pin located behind theformer, a fulcrum block in which the pivot pin is journalled, whichblock is mounted to slide horizontally between guide plates upon theframe in any direction to afford pivotal movement of the arm aboutdifferent parallel axes, the flat table on the arm below the former, ashoe able to roll in a horizontal plane of movement on a work pieceplaced against the former, which shoe rests on the table and is capableof being slid over it linearly and angularly in any direction, a mainhydraulic piston and cylinder unit mounted on the arm to press the shoeagainst the workpiece on the former, said main piston and cylinder unitbeing provided with a roller nose to apply the pressure to the shoe,which nose moves laterally as the arm swings thereby shifting the placeof contact between roller nose and shoe along the shoe, and a pair offucrum-moving hydraulic piston and cylinder units mounted upon themachine frame with their axes lying substantially at right angles to oneanother in a horizontal plane, said fulcrum-moving piston and cylinderunits being operatively connected to the fulcrum block for sliding it tovarious positions to cause the arm, when pressure is applied to theworkpiece by the main piston cylinder unit and shoe, to swing and effectsaid lateral movement of the roller nose to shift the place ofapplication of pressure to the workpiece by the shoe progressively alongthe workpiece.

9. In a metal-working machine the combination of a machine framecomprising a base, supports upstanding from the base and a bridge memberextending transversely of the machine between the supports and above thebase, a former support member depending from the bridge mem ber, aformer secured above the base upon the lower end of the former supportmember, said former having a curved profiled face to receive a workpiecefor shaping, which profiled face extends endlessly all around the formerso that said face is in the form of a closed figure, an elongated armmounted on the frame to be capable of swinging in a horizontal planeabout a fulcrum located within the closed figure of the profiled face ofthe former in a manner to change the crossing angle of the longitudinalarm axis and the form er profile and through a complete revolutionaround the former, said fulcrum being movable upon the machine frame inthe horizontal plane to afford pivotal movement of the arm aboutdifferent parallel axes, a press-member supported on the arm to bear ona workpiece placed against the former, fluid-pressure-operated meansmounted on the arm to urge the press-member toward the former, andfulcrum-moving means mounted upon the machine frame and operativelyconnected to the arm at the fulcrum end thereof within the closed figureof the profiled face of the former for moving said fulcrum to variouspositions within the closed figure of the profiled face of the former tocause the arm, under the eifect of pressure applied to the workpiece bythe fiuid-pressure-operated means and press-member, to swing and shiftthe place of application of pressure progressively along the workpiece.

10. In a metal-working machine the combination of a machine framecomprising a base, supports upstanding from the base and a bridgememberextending transversely of the machine between the supports and above thebase, a former support member depending from the bridge-member, a formersecured above the base upon the lower end of the former support member,said former having a curved profiled face to receive a workpiece forshaping, which profiled face extends endlessly all around the former sothat such face is in the form of a closed figure, an arm mounted on theframe to swing in a horizontal plane through a complete revolutionaround the former about a pivot pin located within the closed figure ofthe profiled face of the former, a fulcrum block in which the pivot pinis journalled, which block is mounted to slide horizontally betweenguide plates upon the frame in any direction to afford pivotal movementof the arm about different parallel axes, a flat table on the arm belowthe former, a shoe able to roll in a horizontal plane of movement on aworkpiece placed against the former, which shoe rests on the table andis capable of being slid over it linearly and angularly in anydirection, a main hydraulic piston and cylinder unit mounted on the armto press the shoe against the workpiece on the former, said main pistonand cylinder unit being provided with a roller nose to apply thepressure to the shoe which nose moves laterally as the arm swingsthereby shifting the place of contact between roller nose and shoe alongthe shoe, and a pair of fulcrum-moving hydraulic piston and cylinderunits mounted upon the machine frame with their axes lying substantiallyat right angles to one another in a horizontal plane, saidfulcrum-moving piston and cylinder units being operatively connected tothe fulcrum block for sliding it to various positions within the closedfigure of the profiled face of the former to cause the arm, whenpressure is applied to the workpiece by the main piston and cylinderunit and shoe, to swing and effect said lateral movement of the rollernose to shift the place of application of pressure to the workpiece bythe shoe progressively along the workpiece.

UNITED STATES PATENTS References Cited in the file of thi patent, NumberName Date 1,714,083 Frank May 21, 1929 1,935,604 Abramson Nov. 21, 19332,142,443 Goin Jan. 3, 1939 2,148,748 Hardy Feb. 28, 1939 2,255,867Wisckol Sept. 16, 1941 2,287,933 Green June 30, 1942 2,305,850 DrysdaleDec. 22, 1942 2,444,718 Bath July 6, 1948 2,501,241 Shaw Mar. 21, 1950

